OVERKILL
$100 Site Donor 2021
Ok, the indie performance shop I know, that offers RP as a choice (API, HPS and HMX) has never seen purple dyed engines. Be it recently or in the past. Never.
We do have our buddy Google! LOL! I think it was @RDY4WAR who noted that he's seen it before.
Do the pictures from this thread show up for you?
royal purple =sludge - LS1TECH - Camaro and Firebird Forum Discussion
Forced Induction - royal purple =sludge - I just pulled my oil pan today and I must of had a 1/4in of thick black nasty tar like sludge in the pan the pick up tube had tar like residue on it and the screen was about a 1/4 blocked with sludge. I ran mobil 0ne for the first 10-15k miles and then...
ls1tech.com
If not, here's one of them:

Of course like anything on the internet, I'd take what's presented in that thread with a giant grain of salt.